In a since-deleted message on his Instagram account, her boyfriend, Luke Storey, shared some sweet words about the model with his 44,500 followers, describing her as "one of the kindest, sweetest, purist people [he'd] ever met." "In many ways you were my first and only fan who always spoke to me about my music, telling me how important it was and encouraging me to write more and more," he wrote in the message. "We understood each other from the get-go." Later in the message, Storey admitted that she was the only one by his side when he relapsed in his apartment. "I saw in you what I carry, too," he confessed. "I wish we had spent more time together sober, but we rarely were. Too busy running away from our demons. Keeping each others pain in perfect company. We were pain twins."

"It could have been me, or anyone in our circle of maniacs. I think it should have been me," he continued. "I’m f**king angry. I’ve got nothing else. Félicité, you graced my life in such a short time and I will now miss you forever. I know you’d want me to stay clean and stay creating so that’s what I’ll do until I come and look for you on the other side."

As we previously reported, the former One Direction bandmate's sister died after suffering a heart attack. TMZ reported that Félicité passed away on Wednesday (March 13) at her apartment in London. She reportedly collapsed and was unable to be revived by paramedics. She was a model and fashion designer with a 1.3 million following on Instagram. Félicité’s death comes just over two years after their mother, Johannah Deakin, died of leukemia in December 2016. "Police were called by London Ambulance Service at 12:52hrs on Wednesday, 13 March to a residential address … following reports of a female in cardiac arrest," the Metropolitan Police told PEOPLE in a statement. "Officers attended. A female believed to be aged 18 was pronounced dead at the scene. At this stage, the death is being treated as unexplained. A post-mortem examination will take place in due course. Enquiries continue."